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Midwest Transplant
| Posted in Construction Techniques on
Hi All,
I have a “best practices” question for you. I’ve completely gutted a 14’x12′ single room extension on my house. I plan to install a non-bearing wall along the 12′ span, parallel to the floor joists. Thankfully, my ceiling joists are incredibly straight. However my floor sags about 1″ at the center of the 12′ span. The extension is 70 years old, the 2×8 joists are still very solid, they’re just sagging. There seems to be quite a difference in opinion about fixing sag in older houses. Honestly, living in an older house, I’m not super concerned about the aesthetics of a bit of sag, however I want to know if you think I should fix the sag for the sake of framing the wall (or any other reason I’m not thinking of). If so, how would you recommend going about it? Keep in mind, I’m stripped down to the dirt in the crawlspace, which is about 24″ below the bottom of the floor joists.
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open ended question involves an open ended answer
There are no "best practices" when it comes to addressing sag in remodels. If the sag is an issue that compromises the structural integrity of your home and/or safety , then my advice is hire a professional engineer and fix it. IMO there is little 'grey' area there. If it truly is only an aesthetic issue, then that remains purley subjective. Only you can determine your level of tolerance regarding the 'perfectly' framed home. Much of that tolerance will be influenced by your budget*. Sure, you can get a myriad of opinions from this forum (or on your bus ride to work) with regard to that subjectivity. However, IMO you'd be chasing your tail trying to decipher who's advice is best and who's advice is least.
One piece of unequivocally good advice I can give you: At some point (preferrably sooner, rather than later) cover that dirt.
*another solitary aspect of your project.
Since you have the entire room gutted, you may as well spend a few hours getting a 2x8 under the center of the room running perpendicular to the joists, then jacking the floor back to level. i would add two piers under the 2x8, and possibly another under the spot where the wall will intersect with the new support. or just try to get your placement right. Disclaimer: you may end up with a little bit of cracking in your plaster or drywall in adjacent rooms, but i would not expect it to be much if anything. i doubt that this is crucial, but it is cheap and relatively easy as long as you are not huge.
I'd install the top and bottom plates, and then measure and cut each stud.
Just a couple of observations:
If the floor is sagged it may bounce a lot or rise and fall seasonally, making the junction with the wall problematic. This potential may be justification for fixing the sag, or at least bracing it up a little.
For basement walls, because of the possible seasonal change, it's not uncommon to suspend the wall from the ceiling and make the floor connection "slide" on pins. A similar thing is sometimes done for walls mated to trusses, so that the wall can rise with the truss and not crack at the corners. The bottom joint is hidden behind baseboard nailed only to the fixed bottom plate, so the wall can slide up/down behind it.
Unless you see a problem with your joist then you more than likely are assessing the problem correctly. I also live in an old house (1904) and althoughy I have addressed most of the floor issues in the house a little bump or dip doesn't bother me either.
If the dip doesn't bother you then I would frame the wall conventionally and make up the gap where you top plate meet your blocking.
Putting in a beam to gain that dip back would be simple since you are looking at your crawl space, another benefit to putting a beam in would be to eliminate the bounce you more than likely have when you walk across the room.